Antibacterial spectrum of produced reuterin from new isolates of Lactobacillus reuteri

Abstract

A total number of 20 samples were collected from different local Iraqi sources. The samples were diluted and inoculated on MRS agar medium. After growth, the isolates were transferred on the modified MRS selective agar medium in order to get isolate of Lactobacillus reuteri which able the reuterin production. Five isolates were obtained from the human infant feces (1-3 months), which were tested by morphological, physio-biochemical assays and molecularly confirmed as L. reuteri by detection of the species gene specific. Electrophoresis of PCR products showed bands at the position 303pb while the sequencing and blasting results of these products were revealed 100% identity of three isolate products to a reference strain L. reuteri ATCC53608 and L. reuteri BPL-36. The fifth residual isolate was limited on physio-biochemical identification as L. reuteri due to failing in sequencing. Infrared spectrum (FT-IR) of extracted reuterin from local isolated was matching with FT-IR of standard reuterin. The antimicrobial inhibitory spectrum of all five isolates was determined against 16 species of gram positive and gram-negative pathogens and food spoilage for their application in food bio-preservation. Escherichia coli and Staphylococcus aureus were observed to be the most affected among the tested organisms, whereas L. acidophilus and L. plantarum were less affected among them.